The present invention relates to building units for exterior walls and, particularly, to lightweight, insulating building units.
Installation and material costs for masonry bricks and blocks for exterior applications continue to steadily increase. As a result, much of the population can no longer afford the attributes of masonry materials for such applications and generally has to settle for non-masonry substitutes. Although various panel type innovations have been developed to simulate masonry construction, even an untrained observer can easily detect the true nature of such substitutes.
Manufacturing methods using injection molding techniques are available which could produce individual building units which would be substantially more cost-effective as compared to the costs of conventional masonry products. Such a material would preferably be strong, lightweight, fire-retardant, non-toxic, inexpensive, impervious to moisture penetration, and not affected by sunlight or inclement weather conditions. Polyvinylchloride, and particularly PVC 7042, is particularly adapted to provide these characteristics.
Further, structures which are constructed with conventional masonry units may need to be periodically treated to prevent moisture penetration both through the masonry units themselves and through the mortar joints separating the masonry units. Building units constructed of polyvinylchloride could be cemented and bonded together with a resilient waterproof sealant, such as silicone caulking, thereby forming a waterproof and airproof joint between building units to supplement the waterproof and airproof barrier also provided by the building units themselves. In addition, such joints between the building units would provide the resiliency and flexibility needed to Withstand normal structural shifting and movement which causes cracking and separation in conventional masonry walls. Another benefit would be the elimination of having to properly combine ingredients for, mix and promptly use conventional mortar.
Also, considerable skill is generally required to properly position each masonry unit relative to adjoining and underlying masonry units in order to obtain acceptable, plumb workmanship. Alignment elements formed integrally in the building units could be utilized to automatically space and align each building unit being installed relative to those building units already installed. As a result, do-it-yourselfers could easily install such units, whereby additional cost effectiveness is realizable by eliminating expensive, highly skilled labor.
Conventional masonry units provide some insulating properties but such characteristics sometimes arise more from the heat energy stored in the bulk of the conventional masonry units rather than from dead-air space therein and low heat conductivity characteristics thereof. As a result, the insulating factor realized with conventional masonry units generally leaves much to be desired.
What is needed is a building unit which does not require considerable skill to properly align with adjoining and underlying units, which is lightweight, which has excellent insulating characteristics, and which is substantially impervious to moisture thereby eliminating the need for periodic weatherproofing treatments.